666731611 has 8 divisors (see below), whose sum is σ = 820592864. Its totient is φ = 527523840.

The previous prime is 666731599. The next prime is 666731617. The reversal of 666731611 is 116137666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666731611 - 2¹¹ = 666729563 is a prime.

It is a super-2 number, since 2×666731611² = 889062082213310642, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666731617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3663270 + ... + 3663451.

It is an arithmetic number, because the mean of its divisors is an integer number (102574108).

Almost surely, 2^666731611 is an apocalyptic number.

666731611 is a deficient number, since it is larger than the sum of its proper divisors (153861253).

666731611 is a wasteful number, since it uses less digits than its factorization.

666731611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7326741.

The product of its digits is 27216, while the sum is 37.

The square root of 666731611 is about 25821.1465856960. The cubic root of 666731611 is about 873.6088308657.

The spelling of 666731611 in words is "six hundred sixty-six million, seven hundred thirty-one thousand, six hundred eleven".